How hot is too hot?

[Sleedo]

My motors are getting too hot to touch for more than a few seconds after a 7min test cut. I am running them at 12v as at 5v from my PC PS they weren't strong enough to move my foam cutter. The motors in question are nema 17 Vexta PX245s they are rated 6V 0.8A on the label. Am I over driving them and risking damage?

Sleedo

[paulC]

What are you using to drive the steppers? Does it use a chopper curcuit and what is the current limit set to? If not what current limiting are you using?

[Sleedo]

Paul, my board is the Foamlink board, picked it up used and I don't have any info on it. There are heatsinks attached to the chips so I couldn't even tell you what they are. Sorry I am a complete newb, just looking for some guidance. I suspect that the cheap motors that I bought bought were no bargain because the don't have the torque that I need.

Sleedo

[Cubster]

If the nominal voltage is 6V you should drive it with that voltage, lower (I mean 5V) and higher (more than 7V) with result in temperature issues.

About the motor's weakness:
Try to activate double polarization if your drive board can do it.

Some tips:
Double polarization means double the current from the power supply (0,8Amp. x 2)
Maybe your power supply it's only 12V 1Amp, the overcurrent demand drives less voltage and get's everything hot.

Use the exact voltage and a power supply with oversized nominal currents.